This invention relates to wearable apparatus for providing facial muscular biofeedback.
Facial wrinkles can develop for a variety of reasons and are generally classified as either static or dynamic. Static wrinkles are the wrinkles and folds of the skin that are present when the face is at rest and the facial muscles are not acting on the skin so as to form a facial expression. Dynamic wrinkles are those that occur due to the effects of facial muscle activity on the overlying skin. With age, stress and environmental damage (such as sun exposure and smoking), dynamic wrinkles eventually become static wrinkles.
For many people, facial wrinkles are unwelcome and various treatments are available to reduce the appearance and/or development of wrinkles. For example, chemodenervation by means of a botulinum toxin injection can be used to reduce activity in certain facial muscle groups so as to prevent those muscles causing dynamic wrinkling of the skin that might lead to the development of static wrinkles. The most common site for a botulinum toxin injection is at the glabellar (frown) lines between the eyebrows. Other treatments suitable for the treatment of dynamic wrinkles include cosmetic surgery and dermal filler injections. All of these treatments are invasive, can involve some pain, and must be performed by a skilled practitioner.
Excessive activation of the facial muscles (e.g. due to habitual squinting or frowning) has also been found to be a factor in the occurrence of headaches and migraines. Recently, the use of botulinum toxin injections has been extended to treat headaches and migraine, with some studies finding complete or partial resolution in 75% of patients. Furthermore, significant numbers of patients received botulinum toxin injections for cosmetic indications report beneficial effects on headaches. Recent studies have also demonstrated that botulinum toxin injections into the frown area blocks frowning and elevates mood in depressed patients.
The facial muscles can themselves be affected by facial movement disorders such as hypertonia (increased muscle tone), synkinesis (abnormal and uncoordinated involuntary muscle activity) and hyperkinesia (exaggerated muscle activity). These disorders are frequently seen after facial nerve trauma and it is postulated that there is a “mis-wiring” of the nerves which results in inappropriate signals being sent to certain muscles (e.g. closing the eyes results in activation of smile muscles and vice versa). Hypertonia of glabellar and procerus muscles can also be seen in those who habitually squint or frown—for example, due to bright lights, photosensitivity, short-sightedness, use of computers/smartphones, and psychological stress. This can lead to the development of significant facial wrinkles. Such activation of the glabellar and procerus muscles also pulls down the forehead and brow, eventually resulting in hooding of the upper eyelids.
As an alternative to a botulinum toxin injection, STX-Med produce a wearable device “Safetox” that inhibits the activation of the glabellar muscles through the application of an electric potential at the skin overlying the muscle. This can reduce dynamic wrinkles and hence prevent the development of static wrinkles but does not address the underlying cause of the wrinkles in a manner that permanently reduces wrinkling. Specifically, it is not designed to dynamically monitor muscle activity and mediate its effects in response to such activity.
The control of muscle activation can be improved through the use of biofeedback, which allows an individual to learn how to modify the activation of particular muscles by feeding back to the individual information representing measurements of the activation of those muscles. Biofeedback has been found to be useful in the treatment of various conditions such as Bell's Palsy and headaches. A review of general biofeedback practices is presented in “Evidence-based practice in biofeedback and neurofeedback” by C. Yucha & D. Montgomery, Association for Applied Psychophysiology and Biofeedback, 2008.
Devices suitable for enabling biofeedback include the MyoTrac Infiniti manufactured by Thought Technology Ltd. The MyoTrac device can provide an surface electromyographic (sEMG) signal captured from muscles to a computer, with the signal being used to control a video game or animation so as to provide feedback to the user—for example, with the activation of a leg muscle being used to control the ascent of a balloon in a video game. In this manner, the user can learn to improve their muscle control. However, MyoTrac is not suitable for use with facial muscles and does not allow a user to receive useful biofeedback indicative of complex facial expressions whilst engaged in normal everyday activities.
Headsets manufactured by NeuroSky and Emotiv Systems can be used to acquire electroencephalogram (EEG) signals that in practice can determine some aspects of facial movement, but those headsets do not provide any biofeedback to the user and are not therefore suitable for training a user how to improve their muscle control. Details of the NeuroSky and Emotiv Systems headsets can be found in US patent publications 2009/0214060 and 2007/0060830, respectively.
Various other publications deal have suggested using facial muscle activity for: controlling electronic devices, US 2012/0229248 and GB 2396421; monitoring drowsiness, US 2012/0229248 and WO 91/13584; for assessing the psychological state of a user, U.S. Pat. No. 6,102,847; and reducing neuromuscular tension, US 2011/0288445. None of these publications provide wearable apparatus for use whilst engaged in normal everyday activities that can provide biofeedback indicative of a wide range of facial expressions for the treatment of wrinkles and facial movement disorders.
There is therefore a need for improved apparatus for inhibiting or promoting the activity of facial muscles through biofeedback.